Power driven type action for character-by-character printers



Aug 18, 1959 H.l .'rHo| s1-RUP 2,900,063

POWER DRIVEN TYPE ACTION FOR CHARACTER-BY-CHARACTER PRINTERS IN V ENTOR. /VfA//ey l, Hmsr/eap ATTORNEY Aug. .18, 1959 H. l.. THoLsTRUP2,900,063

POWER DRIVEN TYPE ACTION yFOR CHARACTER-BY-CHARACTER PRINTERS originalFiled oct. 4. 1956 e sheets-sheet 2 Y IN V EN TOR. #5A/2y @0L smv/DATTORNEY Aug. 18, 1959 H. L. THoLsTRUP 2,900,063

POWER DRIVEN TYPE ACTION FOR CHARACTER-BY-CHARACTER PRINTERS originalFiled oct. 4. 195e e Smets-sheet s ATTORNEY Aug. 1.8, 1959 H. L.THoLsTRUP 2,900,063

POWER DRIVEN TYPE ACTION FOR CHARAOTER-BYCHARACTER PRINTERS OriginalFiled Oct. 4, 1956 6 Sheets-Sheet 4 IN VEN TOR. #EA/@y L. Kem sffeap ATTOR/VEV Aug. 18, 1959 H. L. THoLsTRUP 2,900,063

POWER DRIVEN TYPE ACTION FOR CHARACTER-By-OHARAOTER PRINTERS OriginalFiled 001'.. 4, 1956 6 Shets-Sheet 5 Tcl. En.

IN V EN TOR. #5N/ey l. @MSM/P Aug. 18, 1959 H. 1 THOLSTRUP 2,900,063

POWER ORIVEN TYPE ACTION POR oHARAcTER-BY-OHARAOTER PRINTERS OriginalFiled Oct. 4, 1956 6 Sheets-Sheet 6 INV ENTOR.

BY A 53 W United States Patent i) POWER DRIVEN TYPE ACTHON FORCHARACTER- Bit-CHARACTER PRINTERS Henry L. Tholstrup, Rochester, NX.,assignor tov Commercial Controls Corporation, Rochester, N Y., acorporation of DelawareY Claims.I (Cl.-197 17')` This invention relatesto' a power operated characterby-character printer.' This application isa division of my copending application for United States patent, SerialNo. 613,877, filed October 4, 1956 for Power Driven Printer. l

It is the main object of the invention to provide a printer of the poweroperated typewriter class, in which the printing operation and thefunctions attendant thereon are performed at much greater speedthanobtainable in machines of the same class now available.

The speed at which a printer 'of the power operated typewriter class canbe operated is dependent upon the time required to perform the variousfunctions of such machines. In the average printer of this class, thetype bar speed is 115 milliseconds, the return of the carriage (100spaces) consumes 575 milliseconds, tabulation (50 spaces) requires 455milliseconds, case shifting consumes 85 milliseconds, and a back spacingoperation can be performed in no less than 125 milliseconds with theresult that the average copy can be composed at a maximum rate of notmore than 12 characters per second. Simply to increase the speed of suchconventional printers, considering kinetic energies involved, wouldmerely increase the frequency of service calls and shorten the ultimatelife of the machine. p

It is, therefore, the object of this invention to provide a printerwhich may be operated at much higher speed than heretofore possiblewithout imposing still higher impact loads on the type bars and greaterstrain on other moving functional parts.-

The objectives of the invention are accomplished by providing a positivedrive for the type levers, carriage, etc., thus overcoming accelerationlags inherent inmachines in which type lever action is merely powerinitiated and in which the return movement is under the iniluence ofgravity or light spring tension, or in which carriage movement is merelyunder control of springs. This invention concerns itself particularlywith the positive drive mechanism for the type action.

By providing mechanism for the positive movement of the type levers inboth directions, the printer herein has an average type bar speed ofonly 40 milliseconds with theresult that the typing strokes for averagecopy are increased 35 or more per second;

It is a still further object of the invention to provide a novelmounting for type levers capable of withstanding high speed operation.

It is a further object of the' invention to provide a printer of theclass described in which the type levers are power operated, both in theprinting stroke and in their return to rest in the type basket.

Further objects and advantages of the invention will become apparent as'the specification is read in light of 2,900,063 Patented Aug. 18, 1959Fig. 2 is' a sectional view on line 2 2 of Fig. 1 showing, in plan, apower transmission system and related mechanism;

Fig. 3 is a horizontal section through the rear part of the frame andcasing showing, in plan, certain of the drive mechanism;

Fig. 4 is a view on line 4 4 of Fig. 3, showing the drive mechanism inend elevation;

Fig. 5 is a sectional view on line 5 5 of Fig. 2, illustrating a Genevadrive mechanism;

Fig. 6 is a sectional view on line 6 6 of Fig. 5;

Fig. 7 is a vertical sectional view through the type bar mechanism andits drive and control structures;

Fig. 8 is a sectional View on line 8 8 of Fig. 7;

Fig. 9 is a sectional view on line 9 9 of Fig. 8;

Figs. l0, 11 and l2 showthe mechanism of Fig. 9 in various operationalpositions;

Fig. 13 is a fragmentary plan view of a type basket or segment taken online 13 13of Fig. 7;

Fig. 14 is a sectional view on line 14 14 of Fig. 13; and

Fig. 15 is a sectional view on line 15 15 of Fig. 13.

The power for driving the printer is derived from a motor 10 and istransmitted through an escapement drive unit 12 and an electromagneticclutch unit 14. The relationship of the motor, the escapement drive unitand the electromagnetic clutch unit may ybe seen in Figs. 3 and 4. Themain frame 16 of the printer serves as a housing for these units and asa support for a movable carriage 18 as seen in Fig. 1.

The escapement drive unit 12 and the electro-magnetic clutch unit 14 areso constructed and arranged as to positively drive the carriage 18 inboth forward and return directions. The details of the drive assemblyare fully shown in my above-noted application for United States patent.The motor 10 is adapted to impart uni-directional rotation to a motorshaft 20 which is connected by means of a flexible coupling 22 to adrive shaft 24. The drive shaft 24 is mounted for rotation in' suitableantifriction bearings and has fixed to its distal end a drive shaftpiston 26. The drive shaft pinion 26 meshes with an intermediate gear28, which is fixed to the inner end of a pulley shaft 30 which issuitably journalled for rotation.

By reference to Fig. 3, it will be seen that the pulley shaft 30 extendstransversely beyond the side of the printer frame 16 where it has tixedthereto a pair of V-drive pulleys 32. These pulleys accommodate a pairof drive belts 34 for driving a shaft 36 (Fig. 2) through which power istransmitted to a Geneva drive which is illustrated in some detail inFigs. 5 and 6. The shaft 36 has xcd thereto a Geneva pin plate 38 whichhas four pins 40 extending from the inner face thereof. The pins 40 areadapted to engage respective slots l42. in a Geneva disc 44. The Genevadisc is fixed to a power shaft 46, the power shaft 46 extendingtransversely of thek printer frame in the area of the type actionmechanism. Figs. 7 and 8 show the position of the power shaft 46. f y

It has been stated heretofore that one of the objectives of theinvention is the positive drive of the type levers at all times, ie.,each type lever is not only positively driven into printing engagement,but it is positively driven to its normal inactive position in the typebasket. To obtain an understanding of the mechanisms resulting in thisfunction, reference should be had-to Figs. 7 through l2. v

A complement of type levers 48 is' mounted in a type basket 50 such thateach type lever can be rotated into and out of a common printingposition with respect to a platen 52 mounted on the carriage 18. Thespeed at'which the type levers are adapted to operate precludes the useof a conventional segment wire for mounting the type levers in the typebasket. Consequently, this invention contemplates an improved means formounting the individual type levers in the type Abasket such that theoperational strain of the positive drive can be successfully absorbed.

Figs. 13 through 15 show type lever and type basket structures adaptedto this end.V Each of the type levers 48, as best seen in Fig. 15, 'hasa pivot point in the type basket 50 consisting of a small ball 54 whichis swaged into an eye at the inner end of the type lever. The vtypebasket is segmental in form as in the usual typewriter structure andconsists of a base segment 56 and a locking segment 58. Each of thesegments 56 and 58 has complementary hemispherical concavit'ies forminga bearing pocket 60 (Fig. 14) for the type lever bearing balls 54. Thebearing balls 54 of a complement of type levers are seated in theconcavities of the base segment 56'and are there held in place by thelocking segment 58 which is fixed to the base segment 56 by means of aseries of screws 62.

In a machine adapted to high speed operation, such as the presentmachine, it is important that each of the type levers be retained in thetype basket under substantially the same amount of pressure. In order toaccomplish this particular result, the locking segment 58 andparticularly that part which engages the pivot balls 54 assumes the formof a rim 64 (Fig. 14) which has a slot 66 milled therein therebyimparting a degree of resilience to the rim 64 under which the typelever pivot balls 54 are engaged.

By reference to Fig. 7, it can be seen that each of the type levers 48has formed at the pivot end thereof a gear segment 68. Each type levergear segment 68 is constantly in engagement with mating teeth 70 of arelated bell crank 72. It may be seen, therefore, that whenever the bellcrank 72 of Fig. 7 is rotated in a counterclockwise direction, the typelever 48 which is associated therewith, will be rocked in a clockwisedirection which is the printing stroke. When the bell crank 72 is rockedin a clockwise direction, the type lever associated therewith willberocked in a counterclockwise direction thereby returning the type leverto its normal inoperative position of rest against a type lever stop 74.The mechanism by which the bellcranks 72 are operated and controlledwill now be described. In this connection, it is to be understood thateach type lever of the entire complement of type levers is operated by abell crank assembly such as that shown in Fig. 7.

The bell crank 72 is mounted for rocking movementon a bell crank shaft76 and associated with this bell crank is a drive plate 78 fixed forrotation with the power shaft 46. Extending from one face of the driveplate 78 are a pair of drive pins 80 and 82. These drive pins areadapted to cooperate with elements of the bell crank 72 to drive thebell crank in the manner heretofore described.

`The bell crank assembly is best understood by reference to Fig. 9 inwhich it is seen that the bell crank 72 carries a bell crank latch 84, aguide plate 86, a stop pawl 88 and a pair of lugs 90 and 92. The bellcrank latch 84 is pivoted on the bell crank 72 by means of a pivot pin94. The bell crank latch 84 is biased about the pivot pin 94 in acounterclockwise direction by means of aV spring 96 which extendsbetween the free end of the bell crank latch 84 and the bell crank 72.The bell crank latch 84 is normally held in retracted position, as shownin Figs. 7 and 9, by a bell crank trip lever 98. The'bell crank triplever 98 is pivoted on a trip lever shaft 100 about which it is normallybiased in a counterclockwise direction by a spring 102 connecting theupper end of the bell crank trip lever 98 with a casing 104 in which thebell crank assembly is located. The bell crank trip lever is generallyL-shaped and Vhas an inwardly extending leg 106, which at its free endhas a downwardly extending finger 108 adapted to engage a latch point110 at the lower end of the bell crank latch 84. While the linger 108and the latch point 110 are engaged as shown in Figs. 7 and 9, the bellcrank latch 84 will be in its retracted position against the tension ofthe spring 96.

It has been stated heretofore that the power shaft 46 is rotatingconstantly with the result that the drive plates 78 also rotateconstantly. So long as the bell crank latch 84 is in its retractedposition, the pins 80 and 82 of the associated drive plate 78 willrotate freely in respect to the bell crank'72. In this connection, itshould be noted that the pins and 82 extend into proximity to the faceof the bell crank 72 such that if the bell crank latch 84 is released,the lower free end 112 of the bell crank latch will be engaged by eitherof these pins with the result that the bell crank 72 will be driven in acounterclockwise direction about the bell crank shaft 76.

In order to control the operation of the bell cranks there has beenprovided a plurality of key magnets 114, one for each bell crank,arranged in two staggered rows across the front of the printer. The keymagnets are adapted for selective energization under control of a signalsource such as a punched tape as more fullyl disclosed in my aforesaidapplication for United States patent. Each key magnet has a trip pin 116in contact with an armature 118. Thus, for example, if the magnet 112 ofFig. 7 is energized, it will attract its armature 118 and thereby movethe associated trip pin 116 rearwardly. The armatures 118 are normallyheld away from their related magnets by means of a spring 120. The trippin 116 of Fig. 7, for example, when operated by reason of energizationof its related key magnet, will rock the bell crank trip lever 98 in aclockwise direction about the trip lever shaft 100. This will serve torelease the bell crank latch 84 so that its spring 96 will rotate thelatch 84 in a counterclockwise direction about its pivot 94 and therebyproject the free end 112 of the bell crank latch 84 into the path of thedrive pin 80, for example, thereby conditioning the bell crank 72 foroperation. The tension of the spring 102 which is connected to the bellcrank trip lever 98 is suicient to return the trip pin 116 to its normalinoperative position when Vits related armature 118 is released by thekey magnet 114.

It is now possible to follow an operative cycle of a bell crank assemblyand for this purpose further reference should be made to Figs. 10, 11and 12.

As previously stated, the normal inoperative or rest position of thebell crank is that shown in Fig. 9, wherein the 'bell crank trip lever98 engages the latch point 1'10 of the bell crank latch 84. It has alsobeen previously stated that the trip pin 116, when projected rearwardlyby its associated key magnet armature 118 will rock the bell crank triplever 98 and release the bell crank latch 84. This is the condition ofthe parts illustrated in Fig. 10. It will be noted that the free end 112of the bell crank latch 84 in Fig. 10 is now in the orbit of the drivepin 80. As the drive pin 80 is rotated in a clockwise direction, itscontact with the free end 112 of the bell crank latch 84 will result ina counterclockwise movement of the bell crank 72 about the bell crankshaft 76. This movement will continue until the slot formed between lugon the face of the bell crank and the adjacent end of the guide plate 86coincides with the path of the drive pin 80. At this moment, the drivepin 80 will enter the slot, as shown in Fig. 11. At the moment the drivepin 80 is at the inner 'end of the slot, the bell crank 72 will havebeen rotated labout the bell crank shaft 76 to an extent such that thetype lever 48 is driven against the platen and a typing impressionresults. As the pin'80lcontinues in its orbit of movement, it will enterthe slot formed between the lug 92 on the face of the segment 72 and theadjacent end of the guide plate 86. At this moment, the lug 92 isengaged by the drive pin 80 with the result that the segment 72 is nowrocked in a clockwise direction about the bell crank shaft 76. Thisresults in the counterclockwise movement of the type lever 48 such thatby the time the bell crank 72 has been driven to the extent of itsmovement by the drive pin 80, the bell crank 72 will have been returnedto the position substantially as shown in Fig. 9 and the type lever 48will have been restored to its position against the type lever stop 74,as shown in Fig. 7.

It will be noted that the drive pin 82 has played no part in theoperation of the bell crank in the cycle above described. However, sincethe power shaft 4,6 has been rotated substantially 180, the drive pin 82is now in position to pick up the bell crank as heretofore described. Inother words, the drive pin 82 now occupies the same relative positionoccupied by the drive pin 80 of Fig. 9. If the bell crank latch is againin the orbit of the drive pins, the drive pin 82 will serve to drive thebell crank through the next cycle 0f operation. It is evident,vtherefore, that the bell crank and consequently the type lever can beoperated twice during each revolution of the power shaft thereby greatlyincreasing the printing speed presently inherent in similar printerswhich operate a type lever orllyfl once during each complete revolutionof the'power s a After each operative typing cycle, the bell crank 72 isrelatched in its normal position of rest. This latching operationfollows from the fact that the bell crank latch 84 and particularly theupper end thereof is brought into contact with a stop 122 whicheffectively rocks the bell crank latch in a counterclockwise directionabout its pivot 94 thereby depressing the latch point 110, so that itwill be engaged by the finger 103 of the bell crank trip lever 98. Theelements involved in the relatching operation are conditioned for therelatching of the bell crank latch at the time the bell crank is rockedto its limit position during the typing stroke, i.e., the positioncorresponding generally to that shown in Fig. l1.

It can now be seen that any one o-f a complement of type levers can beselected for operation during any half revolution of the power shaft 46by releasing its associated bell crank assembly for operation. Sinceeach bell crank assembly has its individual bell crank trip lever andtrip pm, the type levers may be sequentiallycaused to operate byselectively energizing the key magnets in the Ides1red sequence andthereby operating a selected trip pin for controlling its related bellcrank assembly.

The key magnets, one for each trip pin, are arranged in a frame alongthe fro'nt of the printer. These magnets, as seen in Fig. 7, arearranged in anupper and lower row, so that they can be somewhatstaggered in relation to each other. Accordingly, the magnets intheupper row, as seen in Fig. 7, attract the armatures 11S, whereas themagnets in the lower row attract armatures which are oppositelydisposed. By way of example, it can be seen in Fig. 7, that the magnet114e of the lower row of magnets has assoclated therewith an armature11851' which is pivoted on the magnet frame and biased into its releasedposition by means of the spring 120e. A common, retaining bar'lltaextends across the magnet assembly and serves to limit the movement ofthe armatures in the outward direction. The key magnets areconventionally under control of a punched paper tape reader and codetranslating system, such as that shown in my Patent No. 2,461,451,issued February 8, 1949. In tape reading systems of this generalcategory, a plurality o-f transversely arranged character-representingholes are sensed and the combinational code so sensed is -translated toproduce a single impulse representative of a character. These impulsesare conducted to the key magnets of the present invention by means ofsuitable electrical conductors connected to the individual key magnetscorresponding to the characters represented by the several impulses.

In accordance with the provisions of the patent statutes, I have hereindescribed the principles of operation of the invention, together `withthe elements which I now consider the best embodiments thereof, but Idesire to have it understood that the structure disclosed is onlyillustrative and the invention can be carried out by other means. Also,while it is designed to use the various features and elements in thecombinations and relations described, some of these may be altered andmodified without interfering with the more general results outlined.

I claim:

l. In a power operated typewriter, a constantly rotatable power shaft, adrive pin carried by said power shaft, a type lever mounted foroscillation into and out of typing position, a pivot shaft mountedparallel to said power shaft, a typing segment for said type levermounted on said pivot shaft for oscillation thereon, a gear segment onsaid type lever, a gear segment on said typing segment disposed inengagement with said first named gear segment, a movable abutmentpivoted to said `typing segment, and means for moving said abutment intothe path of said drive pin, thereby coupling said typing segment withsaid power shaft to oscillate said typing segment on said pivot shaft.

2. In a power operated typewriter, a constantly rotatable power shaft, adrive pin carried by said power shaft, a type lever mounted foroscillation into and out of Ityping position, a pivot shaft mountedparallel to said power shaft, a typing segment for said type levermounted on said pivot shaft for oscillation thereon, a gear segment onsaid type lever, a gear segment on said typing segment disposed inengagement with said first named gear segment, an abutment pivoted tosaid typing segment, means normally urging said abutment into the pathof said drive pin, a latch -for maintaining said abutment out of thepath of said drive pin, and means for releasing said latch, therebycoupling said typing segment with said power shaft to oscillate saidtyping segment on said pivot shaft.

3. In a power operated typewriter, a constantly rotatable shaft, a drivepin carried by said power shaft, a type lever mounted for oscillationinto and out of typing position, a pivot shaft mounted parallel to saidpower shaft, a typing segment for said type lever mounted on said pivotshaft for oscillation thereon, a gear segment on said type lever, a gearsegment on said typing segment disposed in engagement with said rstnamed gear segment, an abutment pivoted to said typing segment, meansnormally urging said abutment into the path of said drive pin, a latchfor maintaining said abutment out of the path of said drive pin, andelectromagnetic means for releasing said latch, thereby coupling saidtyping segment with said power shaft to oscillate said typing segment onsaid pivot shaft.

4. In a power operated typewriter, constantly rotatable power shaft, atype lever mounted for oscillation into and out of typing position, apivot shaft mounted parallel to said power shaft, a typing segment forsaid type lever mounted on said pivot shaft for oscillation thereon, apositive rolling connection between said type lever and said segmentwhereby oscillation 'of said segment will oscillate said type lever, adrive pin rotatable with said power shaft and located to rotate adjacenta face of said typing segment, a movable abutment on said face o-f saidtyping segment, means for moving said abutment into the path of saiddrive pin whereby said segment is Idriven to operate said type leverinto typing position, a second abutment on said typing segmentengageable by said pin when said type lever is in typing position fordriving said segment to move said type lever out of typing position, andmeans thereafter operative for holding said movable abutment out ofthe'path of said pin.

5 In a power operated typewriter, a constantly rotatable power shaft, atype lever mounted for oscillation into and out of typing position, apivot shaft mounted parallel to said power shaft, a typing segment forsaid type lever mounted on said pivot shaft for oscillation thereon, apositive rolling connection between said type lever and said segmentwhereby oscillation of said segment will oscillate said type lever, adrive pin rotatable with said power shaft and located to rotate adjacenta face of said typing segment, a movable abutment on said face of saidtyping segment, means for moving said abutment into the path of saiddrive pin whereby said segment is driven to operate said type lever intotyping position, a second abutment on said typing segment engageable bysaid pin when said type lever is in typing position for driving saidsegment to move said type lever out of typing position, means thereafteroperative to latch said movable abutment out of the path of said pin,and selective means for releasing said latching means.

6. In a power operated typewriter7 a constantly rotatable power shaft, atype lever mounted for oscillation vinto and out of typing position, apivot shaft mounted parallel to said power shaft, a typing segment forsaid type lever mounted on said pivot shaft for oscillation thereon, apositive rolling connection, between said type lever and said segmentwhereby oscillation of said segment will oscillate said type lever, adrive pin rotatable with said power shaft and located to rotate adjacenta face'of said typing segment, a movable abutment on said face of saidtyping segment, means for moving said abutment into the path of saiddrive pin whereby said segment is driven to operate said type lever intotyping position, a second abutment on said typing segment engageable bysaid pin when said type lever is in typing position for driving saidsegment to move said type lever out of typing position, a latchthereafter operative for holding said movable abutment out of the pathof said pin, and electromagnetic means for releasing said latch.

7. In a power operated typewriter, a constantly rotatable power shaft, atype lever mounted for oscillation into and out of typing position, apivot shaft mounted parallel to said power shaft, a typing segment forsaid type lever mounted on said pivot shaft for oscillation thereon, apositive rolling connection between said type lever and said segmentwhereby oscillation of said segment will oscillate said type lever, apair of drive pins rotatable with said power shaft and located to rotateadjacent a face of said typing segment, a movable abutment on said faceof said typing segment, means for moving said abutment into the path ofone of said drive pins whereby said segment is driven to operate saidtype lever into typing position, a second abutment on said typingsegment engageable by said one pin when said type lever is in typingposition for driving said segment tornove said type lever out of typingposition, and means thereafter operative to withdraw said abutment fromthe path of said pins before the second of said pins is rotated intocontact therewith.

8. In a power operated typewriter, a constantly rotatable power shaft, atype lever mounted for oscillation into and out of typing position, apivot shaft mounted parallel to said power shaft, a typing segment forsaid type lever mounted on said pivot shaft for oscillation thereon, apositive rolling connection between said type lever and s`aid segmentwhereby oscillation of said segment will oscillate said type lever, adrive pin rotatable with said power shaft and located to rotate adjacenta face of said typing segment," a pivoted abutment on said face of saidtyping segment, a spring normally urging said abutment into the path ofsaid drive pin whereby said segmentv is rocked aboutsaid pivot shaft inone direction to operate said type leverfintoA typing position, a fixedabutment on said typing segment engageable by said pin when said typelever is in typing position for rocking said segment about said pivotshaft in the other direction to move said type lever out of typingposition, and a latch thereafter operative for holding said pivotedabutment out of the path of said pin. Y

9. In a power operated typewriter, a constantly rotatable power shaft, atype lever `mounted for oscillation into and out of typing position, apivot shaft mounted parallel to said power shaft, a typing segment forsaid type lever mounted on said pivot shaft `for oscillation thereon, apositive rolling connection between saidrtype lever and said segmentwhereby oscillation of said segment will oscillate said type lever, adrive pin rotatable with said power shaft and located toV rotateadjacent a face of said typing segment, a pivoted abutment on said faceof said typing segment, a spring normally urging said abutment into thepath of said drive pin whereby said segment is rocked about said pivotshaft in one direction to operate said type lever into typing position,a xed abutment on said typing segment engageable by said pin when saidtype lever is in typing position for rocking said segment about saidpivot shaft in the other direction to move Said type lever out of typingposition, -a latch thereafter operative for holding said pivotedabutment out of the path of said pin, and selective means for releasingsaid latch to render said type lever operative.

10. In a power `operated typewriter, a constantly rotatable power shaft,a type lever mounted for oscillation into and out of typing position, apivot shaftmounted parallel to said power shaft, a typing segment forsaid type lever mounted on saidpivot shaft for oscillation thereon, apositive rolling connection between said type lever and said segmentwhereby oscillation of said segment will oscillate said type lever, adrive pin rotatable with said power shaft and located to rotate adjacenta face of said typing segment, a pivoted abutment on said face of saidtyping segment, a spring normally urging said abutment into the path ofsaid drive pin whereby said segment is rocked about said pivot shaft inone direction to operate said type lever into typing position, a xedabutment on said typing segment engageable by said pin when said typelever is in typing position for rocking said segment about said pivotshaft in the other direction to move said type lever out of typingposition, a latch thereafter operative for holding said pivoted abutmentout of the pathof said pin, and electromagnetic means for releasing saidlatch to render said typing lever operative.

References Cited in the file of this patent UNITED STATES PATENTS1,785,999 Bryce Dec. 23, 1930 1,924,140 Von Reppert Aug. 29, 19332,119,928 Salzberger June 7, 1938

